Bleaching Tray is also called Teeth Whitening Trays. They're plastic retainers made using models of your teeth that hold the whitening (bleach) gel. Bleaching Tray involves bleaching your teeth to make them lighter. Although it can't make your teeth brilliant white, it can lighten the existing colour by several shades. Bleaching Tray can be a very effective way of lightening the natural colour of your teeth without removing any of the tooth surface. It's a popular and affordable way to make your teeth sparkle.